1. Field of Invention
The invention relates to a shielding module and, in particular, to a shielding module, which has a connection component and is used in an electrical apparatus.
2. Related Art
Most of electrical apparatuses work accompanying with electromagnetic radiation, and different electrical apparatuses are always interfered to each other due to the electromagnetic radiation. This is so-called electromagnetic interference (EMI), which may affect other electrical apparatus. More particularly, electrical apparatuses of high sensitive may malfunction, and human body may be injured.
Electromagnetic waves appear as two forms, including irradiation and conduction. When the frequency of an electromagnetic wave is less than 10 MHz, the electromagnetic wave appears as the form of conduction. When the frequency of an electromagnetic wave is greater than 10 MHz, the electromagnetic wave always appears as the form of irradiation. To prevent the radiation and interference of electromagnetic waves, the containers and conducting wires of electrical products should include high-electromagnetic-conducted materials for shielding electromagnetic waves. In such a case, the thickness of a shielding device should be thicker for shielding electromagnetic waves of lower frequency, and that of the shielding device should be thinner for shielding electromagnetic waves of higher frequency.
To reduce the EMI, a conventional electrical apparatus 1, as shown in FIG. 1, provides a shielding cap 12, which is made of an electric-conducted material, on an electrical device 11. The shielding cap 12 has connection pins 121 for assembling with a circuit board 13, so that the electrical device 11 can be contained between the shielding cap 12 and the circuit board 13. The shielding cap 12 is capable of erasing the accumulation of static electricity and absorbing electromagnetic field. Thus, the electromagnetic wave can be shielded, and the EMI is prevented.
Since the present electrical products become more compact and lighter, and the heat generated by electrical devices is increased, the heat density is rapidly increased. The heat of the electrical devices may not be dissipated easily. Therefore, if the heat-dissipating mechanism for the electrical devices is ineffective, the performance and reliability of the electrical product is deathly affected. Moreover, the lifetime of the electrical product is shortened.
Furthermore, the shielding cap of the electrical apparatus may have an opening for providing a heat-dissipating component on the electrical device, so as to achieve the objectives of heat dissipation and EMI prevention. However, since the heat-dissipating component is attached to the electrical device with an adhesive, the heat dissipation rate is poor. Moreover, since the heat-dissipating component is attached and is not replaced easily, the repairing of the electrical device is difficult when the electrical device has defects. In such a case, the whole circuit board may be discarded as junk.
It is therefore a subjective of the invention to provide a shielding module and an electrical apparatus for solving the above-mentioned problems.